#include <LiquidCrystal.h>
#include <RTClib.h>

#define ENCODER_CLK A0
#define ENCODER_DT  A1
#define ENCODER_SW  A2

int now_hour=0;
int alarm_h=21;
int alarm_m=21;

int sw_flag=0;
int rig_flag=0;
int lef_flag=0;
int lastClk = HIGH;

int sw_val=1;
int sw_val_n=1;
int set=0;

LiquidCrystal lcd(13, 12, 11, 10, 9, 8);
RTC_DS1307 rtc;

void setup() {
  Serial.begin(115200);
  lcd.begin(16, 2);
  rtc.begin();

  pinMode(ENCODER_SW, INPUT_PULLUP);

  pinMode(ENCODER_CLK, INPUT);
  pinMode(ENCODER_DT, INPUT);

  lcd.setCursor(0,0);
  lcd.print("Date:");
  
  // DateTime now = rtc.now();
  // Serial.print(now.year(), DEC);
  // Serial.print(now.month(), DEC);
  // Serial.print(now.day(), DEC);
}

void loop() {
  // Serial.print("hhh\n");
  DateTime now = rtc.now();
  // show_time();
  encoder_det();
  if(sw_flag==1)
  {
    sw_flag=0;
    if(set<2)
      set++;
    else
      set=0;
    Serial.print(set);
  }
  switch(set)
  {
    case 0 : show_time();
              break;
    // case 1 : show_alarm();
    //           break;
    case 1 : if(rig_flag==1)
                {
                  rig_flag=0;
                  if(alarm_h<23)
                      alarm_h++;
                  else 
                      alarm_h=0;
                }
              else if(lef_flag==1)
                {
                    lef_flag=0;
                    if(alarm_h>0)
                        alarm_h--;
                    else 
                        alarm_h=0;
                  }
              // Serial.print(alarm_h);
              lcd.setCursor(8,1);
              lcd.print("_");              
              show_alarm();
              break;
    case 2 : if(rig_flag==1)
                {
                  rig_flag=0;
                  if(alarm_m<59)
                      alarm_m++;
                  else 
                      alarm_m=0;
                }
              else if(lef_flag==1)
                {
                  lef_flag=0;
                  if(alarm_m>0)
                      alarm_m--;
                  else 
                      alarm_m=0;
                }
              // Serial.print(alarm_m);
              lcd.setCursor(8,1);
              lcd.print(" "); 
              lcd.setCursor(13,1);
              lcd.print("_");
              show_alarm();
              break;     
  }
  if(alarm_h==now.hour()&&alarm_m==now.minute())  
    tone(7, 262, 250); // Plays 262Hz tone for 0.250 seconds
}

void encoder_det()
{
  int newClk = digitalRead(ENCODER_CLK);
  if (newClk != lastClk)
   {
    lastClk = newClk;
    int dtValue = digitalRead(ENCODER_DT);
    if (newClk == LOW && dtValue == HIGH) 
    {
      // Serial.println("Rotated clockwise >");
      rig_flag=1;
    }
    if (newClk == LOW && dtValue == LOW) 
    {
      // Serial.println("Rotated clockwise <");
      lef_flag=1;
    }
  }
  sw_val=digitalRead(ENCODER_SW);
  if((sw_val==0)&&(sw_val_n==1))
  {
    sw_flag=1;
    Serial.println("sw");
    delay(10);
  }
  sw_val_n=sw_val;
}

void show_alarm()
{
  lcd.setCursor(0,1);
  lcd.print("Alarm:");
  if(alarm_h<10)
  {
    lcd.setCursor(6,1);
    lcd.print(" ");
    lcd.setCursor(7,1);
  }
  else 
    lcd.setCursor(6,1);
  lcd.print(alarm_h);

  if(alarm_m<10)
  {
    lcd.setCursor(11,1);
    lcd.print(" ");
    lcd.setCursor(12,1);
  }
  else 
    lcd.setCursor(11,1);
  lcd.print(alarm_m);

  lcd.setCursor(9,1);
  lcd.print(" ");
  lcd.setCursor(14,1);
  lcd.print("  ");
}

void show_time()
{
  lcd.setCursor(0,1);
  lcd.print(" Time:");
  DateTime now = rtc.now();
  lcd.setCursor(5,0);
  lcd.print(now.year());
  lcd.setCursor(10,0);
  lcd.print(now.month());
  lcd.setCursor(13,0);
  lcd.print(now.day());
// show hour
  now_hour=now.hour();
  if(now_hour>12)
    {
      now_hour=now_hour-12;
      lcd.setCursor(8,1);
      lcd.print("PM");
    }
  else
    {
      lcd.setCursor(8,1);
      lcd.print("AM");
    }
  if(now_hour<10)
  {
    lcd.setCursor(6,1);
    lcd.print(" ");
    lcd.setCursor(7,1);
  }
  else 
    lcd.setCursor(6,1);
  lcd.print(now_hour);
// show minute
  if(now.minute()<10)
  {
    lcd.setCursor(11,1);
    lcd.print(" ");
    lcd.setCursor(12,1);
  }
  else 
     lcd.setCursor(11,1);
  lcd.print(now.minute());
// show second
  if(now.second()<10)
  {
    lcd.setCursor(14,1);
    lcd.print(" ");
    lcd.setCursor(15,1);
  }
  else 
    lcd.setCursor(14,1);    
  lcd.print(now.second());
  lcd.setCursor(13,1);
  lcd.print(" ");
}